Photoreactive coating for high-contrast spatial patterning of microfluidic device wettability

Abate, Adam R.; Krummel, Amber T.; Lee, Daeyeon; Márquez, Manuel; Holtze, Christian; Weitz, David A.

doi:10.1039/b813405g

Cited by 113 publications

(110 citation statements)

References 21 publications

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“…While Weitz-type glass capillary based devices are inherently hydrophilic, Whitesides-type PDMS devices are hydrophobic and generally treated prior to use [212], with a plasma [213] for instance, to change its wettability. In the case of W/O emulsions, the glass capillary device needs to be adapted which can be easily done via chemical treatment by silanes [214].…”

Section: Droplet Formation In Microfluidic Channelsmentioning

confidence: 99%

Porous polymer particles—A comprehensive guide to synthesis, characterization, functionalization and applications

Gökmen

Prez

2012

Progress in Polymer Science

440

306

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Section: Droplet Formation In Microfluidic Channelsmentioning

confidence: 99%

Porous polymer particles—A comprehensive guide to synthesis, characterization, functionalization and applications

Gökmen

Prez

2012

Progress in Polymer Science

440

306

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“…For the o/w droplets formation, the two T-junctions were grafted poly(acrylamide) (PAA) via photomask assisted to induce hydrophilic surface. 21 For the o/w/o double emulsions generation, the flow-focusing junction was patterned hydrophobic and fluorophilic using perfluorooctyltrichlorosilane immersed for 10 min and followed by ethanol washing for 30 s. Lastly, the whole device was baked at 80 C for 30 min to remove the solvent residues.…”

Section: Surface Modification Of the Microchannelsmentioning

confidence: 99%

Water-actuated microcapsules fabricated by microfluidics

Huang

Zeng

et al. 2011

Lab Chip

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We found a new water-actuated feature of poly(N-isopropylacrylamide) microgels and fabricated microcapsules with this feature based on microfluidic double emulsions. The microcapsules would release encapsulated actives by simple hydration, while forming biphasic hybrid microparticles by gradual dehydration. More complex microcapsules and hybrid microparticles could be produced by varying flow rates and inner oil types. These novel microcapsules could potentially be used for controllable storage or release of chemicals, fabrication of complex microparticles and applications in biochemical fields.Poly(N-isopropylacrylamide) (PNIPAM) microgels are representative intelligent microparticles in response to temperature changes, which swell in water below their lower critical solution temperature (LCST), but shrink dramatically above LCST. 1-3 Due to this unique temperature-actuated feature, microparticles made of PNIPAM have been considered as vigorous candidates for controllable macromolecules release, microsensing and photonic devices. 3,4 However, most reports regarding PNIPAM microparticles have to employ external thermostats to control the surrounding temperature. 3-9 In addition, for the reported PNIPAM microparticles with encapsulated actives (also called ''microcapsules'' 10,11 ), it is difficult for them to release the actives completely when increasing temperature, and this is mainly due to the denser hydrogel shells and hydrophobic interactions, thus, preventing the encapsulated actives from being released 12,13 (see ESI S1 †). Herein, we firstly report a new water-actuated feature of the PNIPAM microgels, and apply this feature in the fabrication of novel microcapsules based on microfluidic double emulsion technology. The synthesized microcapsules could release their encapsulated actives simply by hydration process without temperature stimulus. In addition, the PNIPAM microcapsules could also be transformed to biphasic hybrid microparticles (analogous to ''Janus'' particles 14,15 ) by gradual dehydration. Moreover, by varying flow rates of the fluids and types of the inner oils during the synthesizing process, the microcapsules could encapsulate different inner oil actives and would form diverse hybrid microparticles. These new kinds of microcapsules expand the PNIPAM application and will be of great potential for storage and pulsed release of drugs, development of microsensing and fabrication of complex microparticles.To generate monodisperse PNIPAM microcapsules, we constructed a PDMS microfluidic device consisting of T-junction and flow-focusing geometries, which enabled the generation of pre-gel droplets as templates. The device consisted of a PDMS slab with microchannels and a glass substrate coated by a thinner layer of PDMS membrane, both of them were assembled by plasma treatment. The schematic of the whole device was shown in Fig. 1A. Three immiscible phases: Fluorous oil (FC-40), NIPAM aqueous solution (20%, wt %, with 1% N,N 0 -methylenebisacrylamide as cross-linker) and mineral oil were used as ...

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“…16,17 A number of groups have used alkoxysilanes as silica precursors in order to deposit glasslike surfaces within a PDMS microchannel. These methods have frequently involved elevated reaction temperatures, 11,12,[18][19][20][21] plasma pre-treatment of the PDMS, 12,[21][22][23] or have resulted in significant alteration in the dimensions of the treated microchannel (up to 60% reduction in cross section in a 35 Â 50 lm channel). 12 However, with appropriate reaction conditions, the decomposition of alkoxysilanes can be achieved at room temperature by using either acid-or base-catalyzed hydrolysis.…”

Section: Introductionmentioning

confidence: 99%

A rapid, inexpensive surface treatment for enhanced functionality of polydimethylsiloxane microfluidic channels

Beal¹,

Bubendorfer²,

Kemmitt³

et al. 2012

Biomicrofluidics

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A rapid, inexpensive method using alkoxysilanes has been developed to selectively coat the interior of polydimethylsiloxane (PDMS) microfluidic channels with an integral silicaceous layer. This method combines the rapid prototyping capabilities of PDMS with the desirable wetting and electroosmotic properties of glass. The procedure can be carried out on the open faces of PDMS blocks prior to enclosure of the channels, or by flowing the reagents through the preformed channels. Therefore, this methodology allows for high-throughput processing of entire microfluidic devices or selective modification of specific areas of a device. Modification of PDMS with tetraethoxysilane generated a stable surface layer, with enhanced wettability and a more stable electroosmotic flow rate than native PDMS. Modification of PDMS with 3-aminopropyltriethoxysilane generated a surface layer bearing amine functionalities allowing for further chemical derivatization of the PDMS surface.

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Photoreactive coating for high-contrast spatial patterning of microfluidic device wettability

Abstract: For many applications in microfluidics, the wettability of the devices must be spatially controlled. We introduce a photoreactive sol-gel coating that enables high-contrast spatial patterning of microfluidic device wettability.

Cited by 113 publications

References 21 publications

Porous polymer particles—A comprehensive guide to synthesis, characterization, functionalization and applications

Porous polymer particles—A comprehensive guide to synthesis, characterization, functionalization and applications

Water-actuated microcapsules fabricated by microfluidics

A rapid, inexpensive surface treatment for enhanced functionality of polydimethylsiloxane microfluidic channels

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